Enable Southern Islands (SI) and Sea Islands (CIK) support

The linux package enables AMDGPU support for cards of the Southern Islands (SI) and Sea Islands (CIK). When building or compiling a kernel, CONFIG_DRM_AMDGPU_SI=Y and/or CONFIG_DRM_AMDGPU_CIK=Y should be be set in the config.

Even when AMDGPU support for SI/CIK has been enabled by the kernel, the radeon driver may be used instead of the AMDGPU driver.

To make sure the amdgpu is loaded first use the following Mkinitcpio#MODULES array, e.g. MODULES=(amdgpu radeon).

Set required module parameters

The parameters of both amdgpu and radeon modules are cik_support= and si_support=. They can be set as a kernel parameter or in a configuration file for modprobe in modprobe.d(5).

Set module parameters in kernel command line

To enable full support for SI/CIK when using the amdgpu, set the following kernel parameters to prevent the radeon module from being used [1]:

AMDGPU PRO

To use the proprietary OpenCL component without AMDGPU PRO, installopencl-amdAUR instead.

A downgrade of the linux (4.9) and Xorg (1.18) packages is required to use AMDGPU PRO 17.10.

AMD provides a proprietary, binary userland driver called AMDGPU PRO, which works on top of the open-source AMDGPU kernel driver. The driver provides OpenGL, OpenCL, Vulkan, VA-API and VDPAU support (although this is also supported by the open-source driver). For some workloads it provides better performance than the open-source driver (example benchmark), while for others the contrary is true (example benchmark).

Enable early KMS

Xorg configuration

Xorg will automatically load the driver and it will use your monitor's EDID to set the native resolution. Configuration is only required for tuning the driver.

If you want manual configuration, create /etc/X11/xorg.conf.d/20-amdgpu.conf, and add the following:

/etc/X11/xorg.conf.d/20-amdgpu.conf

Section "Device"
Identifier "AMD"
Driver "amdgpu"
EndSection

Using this section, you can enable features and tweak the driver settings, see amdgpu(4) first before setting driver options.

Tear Free Rendering

TearFree controls tearing prevention using the hardware page flipping mechanism. If this option is set, the default value of the property is 'on' or 'off' accordingly. If this option isn't set, the default value of the property is auto, which means that TearFree is on for rotated outputs, outputs with RandR transforms applied and for RandR 1.4 slave outputs, otherwise off:

Option "TearFree" "true"

DRI level

DRI sets the maximum level of DRI to enable. Valid values are 2 for DRI2 or 3 for DRI3. The default is 3 for DRI3 if the Xorg version is >= 1.18.3, otherwise DRI2 is used:

Option "DRI" "3"

Variable refresh rate

Variable refresh rate (also known as FreeSync) allows the monitor to adjust its refresh rate to the output signal. This allows for games to eliminate screen tearing less usual vsync downsides such as stuttering:

Option "VariableRefresh" "true"

Note:

The monitor and GPU need to support FreeSync and be connected over DisplayPort. HDMI is not supported.

Only OpenGL applications can be adaptively refreshed. RADV Vulkan does not (yet) support FreeSync.

Features

Video acceleration

Overclocking

Since Linux 4.17, it is possible to adjust clocks and voltages of the graphics card via /sys/class/drm/card0/device/pp_od_clk_voltage. It is however required to unlock access to it in sysfs by appending the boot parameter amdgpu.ppfeaturemask=0xffffffff.

Note: In sysfs, paths like /sys/class/drm/... are just symlinks and may change between reboots. Persistent locations can be found in /sys/devices/, e.g. /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/. Adjust the commands accordingly for a reliable result.

To set the GPU clock for the maximum pstate 7 on e.g. a Polaris GPU to 1209MHz and 900mV voltage, run:

# echo "s 7 1209 900" > /sys/class/drm/card0/device/pp_od_clk_voltage

The same procedure can be applied to the VRAM, e.g. maximum pstate 2 on Polaris 5xx series cards:

It is also possible to forbid the driver so switch to certain pstates, e.g. to workaround problems with deep powersaving pstates like flickering artifacts or stutter. To force the highest VRAM pstate on a Polaris RX 5xx card, while still allowing the GPU itself to run with lower clocks, run:

R9 390 series Poor Performance and/or Instability

If you experience issues [6] with a AMD R9 390 series graphics card, set radeon.cik_support=0 radeon.si_support=0 amdgpu.cik_support=1 amdgpu.si_support=1 amdgpu.dpm=1 amdgpu.dc=1 as kernel parameters to force the use of amdgpu driver instead of radeon.

If it still does not work, try disabling DPM, by setting the kernel parameters to: radeon.cik_support=0 radeon.si_support=0 amdgpu.cik_support=1 amdgpu.si_support=1

Freezes with "[drm] IP block:gmc_v8_0 is hung!" kernel error

If you experience freezes and kernel crashes during a GPU intensive task with the kernel error " [drm] IP block:gmc_v8_0 is hung!" [7], a workaround is to set amdgpu.vm_update_mode=3 as kernel parameters to force the GPUVM page tables update to be done using the CPU. Downsides are listed here [8].

Cursor corruption

If you experience issues with the mouse cursor sometimes not rendering properly, set Option "SWCursor" "True" in the "Device" section of the /etc/X11/xorg.conf.d/20-amdgpu.conf configuration file.

If you are using xrandr for scaling and the cursor is flickering or disappearing, you may be able to fix it by setting the TearFree property: xrandr --output HDMI-A-0 --set TearFree on.